Control attachment for weighing machines



July 25, 1950 R, FISCHER 2,516,456

CONTROL. ATTACHMENT FOR WEIGHING MACHINES Filed Aug. 12, 1948 2 sheets-sheet 1 F l G lOl N O INVENTUR.

' RAYMOND FlSCHER ATTORNEY.

R. FISCHER 2,516,455

2 Sheets-Sheet 2 rwmk;

I ATTORNEY.

CONTROL ATTACHMENT FOR WEIGHING MACHINES July 25, 1950 Filed Aug. 12, 1948 Patented July 25, 1.950

CONTROL ATTACHMENT FOR WEIGHING MACHINES Raymond Fischer, Drexel Hill, Pa.

Application August 12, 194s, seriaI No. 43,795'

1 Claim. 1

This invention relates to control attachments for weighing scales and more particularly to an attachment for use with circular dial type scales now in use or for inclusion in such scales at the time of manufacture.

It is the principal object of the present invention to provide control apparatus for use with weighing scales which may be employed in controlling automatic operations in connection with weighing.

It is a further object of the present invention to provide a control attachment for weighing scales having provisions for accommodation of an unknown tare weight and with additional provisions for indicating or controlling weighing operations.

It is a further object of the present invention to provide a weighing machine attachment for control purposes which is suitable for use with existing scales and with which only relatively minor changes are required in the scales for installation.

It is a further object of the present invention to provide an attachment which is particularly useful with weighing scales for automatically placing a predetermined weight of material in a container.

It is a further object of the present invention to provide an attachment for weighing scales which is particularly useful for compensating for the difference in the tare weights of various containers when placing a predetermined amount of material in the containers.

It is a further object of the present invention to provide an attachment for weighing scales which is particularly useful for balancing off the tare weight of an empty container on a weighing scale. Y

It is a further object of the present invention to provide an attachment for weighing scales which utilizes a variable positioned contact arm for making an electrical contact with a correspending contact onjthe pointer of the scale.

Other objects and advantageous features of the `application will be apparent from the speciiication and claim.

The nature and characteristic features of the invention will be more readily understood from the following description, taken in connection with the accompanying drawings forming part hereof, in which:

Figure 1 is a view, partly diagrammatic, showing a weighing scale having mounted thereon apparatus in accordance with the present inventlee;

Fig. 2 is a vertical sectional view taken approximately on the line 2.--2 of Fig. l;

Fig. 3 is a vertical sectional view taken apn proximately on the line 3-3 cf Fig. 2; and

Fig. 4 is a diagrammatic view of a circuit arrangement which may be employed in con` nection with the apparatus of the present invention.

It should, of course, be understood that the description and drawings herein are illustrative merely, and that various modications and changes may be made in the structure disclosed without departing from the spirit of the invention.

Like numerals refer to like parts throughout the several views.

Referring now more particularly to the drawings, a weighing scale of the conventional type is illustrated at I6 and includes a weighing platform II, adapted for the reception of the object or material to be weighed, mechanically or otherwise connected to a movable scale pointer I2. The scale pointer I2 is movable with respect to a graduated scale I3 of the dial type for visual indication of the weight indicating positions of the scale pointer I2. In scales of this type the scale dial I3 is provided customarily with a transparent front cover plate which may be utilized, if there is suiiicient clearance between the cover and the scale dial I3. If there is insuiicient clearance, a housing I4 may be provided extending forwardly from the dial I3 in Which a transparent front coTver plate I5 is mounted. The front cover plate I5 may be of glass, transparent synthetic plastic or the like through which the dial I3 and scale pointer I2 are visible. rihe front cover plate I5 is of a material which is electrically non-conducting.

The control attachment in accordance with the present invention preferably includes a casing portion I8, attached to the front cover plate I5 and having a removable front wall I9. Within the casing portion I8 a shaft 20 is mounted and extends through the plate I5. The shaft 2S has an insulating sleeve 2I thereon on which a concentric hollow shaft 22 is mounted and extends through the plate I5. The shafts 20 and 22 are preferably in frictional engagement with the sleeve 2I so that they normally move together but may be shifted angularly with respect to each other if desired and as hereinafter ex- Dlained.

The shaft 20 has secured thereto, for movement therewith, an indicator and contact arm 23 at the outer end of which an electrical Contact contact 24- and with the contact 28, as hereinafter explained.

The shaft 20 extends forwardly in the casing I8 and is provided awith a knob 3E! for manual adjustment or resetting. The shaft 22 is provided with a gear 3l for engagement by a tongue 32.

The tongue 32 is carried on a pin 33 which is normally held in retracted position by a spring35 and is accessible from the exterior of the casing I8. By manual movement inwardly of the pin 33, against the force of the spring 34 the tongue 32 is engaged with the gear 3 I the shaft 22'is held terminal of the secondary winding of a transl former SI. rlhe other terminal of the secondary winding of the transformer SI is connected to ground and to the conductor 56. The primary winding of the transformer SI is preferably shunted between a conductor 58 connected to the power lead terminal TLI and a conductor 59 connected to the power lead terminal TL2.

A uent material feed control relay 'C may be provided having awinding, one terminal-of which is connected to the conductor 55 and the other terminal of which is connected by a conductor Si! to a contactof a relay D for engagement by a movable contact arm DI when the relay D is deenergized.

-The relay D has a winding, one terminal of which is connected by a conductor BI to the teragainst rotation and the shaft may be turned l with respect thereto by the knob 30. The angular position of the arms 23 and 25 may thus be adjusted as desired.

The shaft 22 has the gear 3| mounted thereon which is connected by a gear 36 to the sha-ft of an electric motor MI, rotatable in a predeter mined direction, for adjustably positioning the pointer arms 23 and 25 at the desired weight indications on the dial I3, and by a gear 31 to the shaftv of an electricV motor rotatable in the opposite direction to that of the motor MI for moving the pointer arms 23 and 2 5 from the positions determined by the motor MI. The motors MI and M2 maybe combined in a single housing and with a single reversible shaft if desired.

The scale pointer- I2 is preferably connected'to' ground by grounding the frame v of the scale I0.

The indicator arm 2.3preferably has an electrical conductor 4I] connected thereto7 the indicator arm has a conductor il connected thereto and power leads 42, 43, 44, and .45 are respectively provided for the motors M2 and MI. The conductors 40, to ,45, inclusive extend respectively to terminals TIO, T2I), TI6, TI5, T1 and T3, at a suitablepanel P.

Referring now more'particularly to Fig. 4 of` the drawings, on which one typicalarrangement of circuit connections for use ywith thecontrol attachment is illustrated, conductors .50, and 5I are provided, connected to terminals TLI and TL2, respectivelyand to a suitable source of ,electrical energy, .suchasa .1.10 volt alternating current supply. Y

Afcontrol relaycAis .provide-dv at the. panel P,v

of any preferred type,and as illustrated has a winding and a-plurality of movable contact arms` AI, A2, A3, andA, al1 of .which are .normally in open circuit position. when the lwinding fis'deenn ergized. The winding of the relay A' has onetern minal thereof connected by a conductor 52 .to a terminal T2 on rthe panelPand the other terminal of the winding of the relay A isv connected by a conductor 53 to almovable Contact arm B2 of a relay B.

The contact arm B2 of the relay B is adapted for engagement with a back contact connected to a conductor 54, when the winding of the relay B, is deenergized, and for engagement with a iront contact connected toa conductor 55 upon ener gization of the winding of the'relayB. The conductor 54 extends to the terminal T1 on the .panel B. The relay B is also provided with-,a contact arm BI adapted for engagement with a Contact connected to a conductorupon energization of the relay B, One terminal of the winding of the relay B is connected' by .a .conductor- 5l tonne minal T25 at the'panel P and the other terminal of which is connected by a conductor 62 to a terminal of a secondary winding of a transformer S2. The other;terminalfofythesecondary Winding is connected,*.to-,eroundpand by aconductor 631:0 a Contact whiohs adapted .fererleaeement by a movablecontact armDZwhen the winding of the relay D is energized.

A,The primary Winding or the transformer S2 is connected .to the yconductor 59 andto the conductor .5B-c2111@ Contact, erm DI` 0f the relay D iS adapted for engagement, .when thewindingof the relay D is decnergized, with the contact to which the conductor Silis connected and when the windina of :the relaaDrs eeereized, with a Conta@ t0 whiclraconductor deis connecteed The conductor 5 4 entendsto .the terminal T15.A A time-r control relay IC is provided, vpreferably adjustableas to the time which elapses before` energizationpfits winding is eiective, 'and has a winding oneterminalf of Vwhich is'connected by a conductor Gfto the terminal'TIE, and the other`4 terminalof whiclii's' connected by a conductor 31' to the .terminal '1| 5 The conductor isconnectedto the conductor 53 vat the contact armv B2,A and bya conductor v69 to a contact for en'-y gagement .by aV contact armTCI- of the relay-TC.. The contact arm TCI is"connected by' a'conduc tor l0 to the conductor59'. The contact arm AII 'is'con'nectedgby a coni; ductor 'l5 to the conductor 58 and is adapted `for engagementwhen the winding of the lrelay A' is energized with a contact which is connected by a.

The contact arm A2 is connected by a conductor TI to thel opposite terminal of thewinding of the relay B to that to .which the conductor 5'lv is connected,` and is connected by a conductor I8 t the contact arm A4... The contact arm A2. is adapted for engagementwitha contact connected by a conductor l@ to the terminal'TlIl. The contactarm` A3 is connected by a conductor 80 to the 'termi nal T20. The contact armV A3 is adapted for engagement with a contact connected by a con-. ductor BI to the contact arm D2 of the relay'D... The contact arm A4 is adapted for engagement with a contact connected by a'con'ductor 82 to they contact arm Blotthe relay B.

The relay C has a contact arm CI connected. by a conductor to a terminal VTIS on vthepanel C. `The contact Varm Cl is adapted for engagementwith a Contact connected by faconductor 86'to' 'a terminal TI5 on the panel P.'v f" The contact arm DI of the relayD is connected by a conductor 8l tothe terminalTS.

vThe terminal TLI is adapted to be. connected. by aconductor 9U to a starting pushbuttonPBV which is adapted to be I'noment'arily pushed;l

establish a connection with a conductor 9| connected to the terminal T2. A stop push button FB2 :is also provided which is adapted to establish a connection between the conductor SI and a conductor 92 which is connected to the terminal The starting push button PBI and the stop push button FB2 may be located at any desired location for easy access by the operator.

The terminals TI 1 and TI8 may be utilized for the connection of indicating or controlling apparatus, if desired, and, where feed control apparatus with automatic control of the feed is desired, a separate power source may be connected by conductors 95 and 96, with the conductor 95 connected to the terminal T I 8, and with conductor 96 connected through solenoid IIII (Fig. l), and a conductor 91 connected to the terminal TI1, leading to the feed control apparatus FC.

The feed controller may be of any desired type and is illustrated diagrammatically as a feed valve IlII controlled by a solenoid IIII and interposed in a fluent material feed line |02. The valve Iti may be urged to closed position by a spring |53 .so that, upon energization of the solenoid ISI feeding is permitted, and upon deenergization, is discontinued or cut off.

The mode of operation will now be pointed out.

The operator adjusts the angular position between the indicator arms 23 and 25 as shown on the scale dial i3 in accordance with the desired Weight of material to be delivered to the container. This may be effected as heretofore indicated. The arms 23 and 25 are also preferably initially positioned by turning the knob 33 so that the arm 23 is beyond and will not be contacted by the pointer I2 when an empty container is placed on the scale platform II and causes movement of the pointer I2.

The operator then places an empty container upon the scale platform Il, and the pointer I2 moves and balances the tare weight. The operator then momentarily pushes the starting pushbutton PBI. The motor MI is energized, by circuits set up as hereinafter explained, and simultaneously advances the arms 23 and 25 until the arm 23 is brought to a position so that its contact 24 engages the contact 21 on the pointer I2. The operation of the motor MI is discontinued and feeding of fluent material to the container is initiated circuits being provided for this purpose as hereinafter explained.

As feeding continues the pointer I2 moves to a position so that its contact 21 engages with the contact 26 of the arm 25. Feeding of fluent material is terminated and operation of the motor M2 is eifected in a reverse direction to that of the motor MI to reposition the arms 23 and 25 at their positions prior to movement of the pushbutton PBI. Operation of the motor M2 is automatically discontinued.

The cycle may be repeated as often as desired and with different tare weights.

If for any reason during the cycle of operations just described it is desired to stop, actuation of the stop button PB2 will cause an immediate discontinuance. The arms 23 and 25 are then manually reset to their initial positions and the cycle may again be initiated by actuation of the starting button PBI.

The manner in which this is accomplished will now be pointed out.

When the starting pushbutton PBI is momentarily pressed a circuit is established for energizing the winding of the relay A which may be traced as follows:

From the terminal TLI, through conductor QU, closed contacts of PBI, conductor SI, conductor 52, Winding of relay A, conductor 53, conductor 58, closed contacts of TCI, conductor 1I] and conductor 59 to terminal TL2.

At the same time a temporary circuit is established to energize the motor Mi which may be traced as follows:

From the terminal TLI, through conductor 9D, closed contacts of PBI, closed contacts of PE2, conductor 92, conductor 45, motor MI, conductor 44, conductor54, contact arm B2, conductor .68, conductor 69, contact arm TCI, conductor 15 and conductor 59 to terminal TL2.

Upon the energization of the winding of the relay A, a circuit is set up through the contact arm AI to maintain the winding energized and continue the operation of the motor MI after the release of the pushbutton PBI. This circuit may be traced as follows:

From the terminal TLl, through conductor 58, conductor 15, contact arm AI, conductor 15, conductor 92, closed contacts of FB2, conductor 9|, conductor 52, winding of relay A, and thence to terminal TL2, as previously pointed out.

Upon the energization of the Winding of the relay A, a circuit is set up through the contact arm A2 for rendering the arm 23 eiiec-tve and energizing the relay B which may be traced follows:

'From the opposite terminal of the secondary of the transformer SI to that connected to ground, through conductor 51, winding of relay B, conductor 11, contact arm A2, conductor 19, conductor 40, arm 23, Contact 24, contact 21 and arm I2 to ground.

Upon the energization oi the winding of the relay B the contact arm BI is actuated to complete a circuit therethrough and through the contact arm A4 to maintain the winding of the relay B energized upon separation of the contacts 24 and 21.

Upon the energization of the winding of the relay B, a circuit is set up for energizing the winding of the relay C which may be traced as follows:

From the terminal TLI, through conductor 58, conductor 15, contact arm AI, conductor 16, conductor 81, contact arm DI, conductor 5D, winding of relay C, conductor 55, contact arm B2, conductor 68, conductor B3, contact arm TCI, conductor B3 and conductor 59 to terminal TL2.

The energization of the winding of the relay C is elective on the Contact arm CI for establishing a circuit through the solenoid IIlI to initiate and permit the flow of fluent material into the container.

Upon the engagement of the contacts 24 and 21, also, the energizing circuit for the motor MI is broken by shifting of the contact arm B2 from its engagement with conductor 54 to engagement with conductor 55.

Upon the energization of the winding of the relay A a circuit is also established through the contact arm A3 for controlling the relay D and rendering the arm 25 effective which may be traced as follows:

From the opposite terminal of the secondary of the transformer S2 to that connected to ground, through conductor 52, winding of relay D, conductor 6I, conductor 4I, indicator arm 25, and when contact 26 engages contact 21 on arm I2, to ground.

Upon the energization of the winding of the relay D, the contact arm D2 is raised to complete a circuit for maintaining the winding energized, and the contact arm is moved to break the circuit through conductor 60 to the winding of the relay C, thus terminating the feed of material to the container, and to establish a circuit for the energization of the motor M2.

This latter circuit may be traced as follows:

From the terminal TLI, through conductor 58, conductor 15, contact arm Al, conductor "I6, conductor 81, contact arm DI, conductor 64, conductor 43, motor M2, conductor 42, conductor 61, conductor B9, contact arm TCI, conductor 10, and conductor 59 to terminal TL2.

The relay TC is adjusted to provide the desired time interval of operation, including operation of the motor M2 and upon the expiration of this time period the contact TCI is opened, thus breaking the operating circuit for the motor M2 and also opening the energizing circuit for the relay A. Upon deenergization of the relay A the relays B and D will likewise be deenergized.

If at any time during the cycle and before completion thereof it is desired to stop, this may be effected by operating the pushbutton PB2. This eiects a deenergization of the relay A with immediate termination of the cycle at that part thereof. The indicator arms 23 and 25 may then be reset manually to the position for starting and operations resumed.

I claim:

Weighing apparatus comprising a Weighing scale having `a weight responsive pointe-i" with an electrical contact, a dial with respect to which said-'pointer is movable, and a'platform for actuating said pointer, control means including a plurality of indicator. arms movable with respect to said dial and each having an electrical contact for contact by said pointer contact, mounting means `for said arms for positioning said arms at the desired angular relation, motor operated means for said mounting means for positioning said arms with respect to said pointer, means actuated upon engagement of the contact `on-one of said indicator arms with the pointer contact for initiating feeding of material to be weighed and for discontinuing feeding upon contact of the contact on another of said indicator arms with said pointer contact.

RAYMOND FISCHER.

REFERENCES CTED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date Re. 21,169 McCrery Aug. 1, 1939 1,785,370 Thomas Dec. 16, 1930 2,199,010 Robb Apr. 30, 1940 Walter Nov. 24, 1942 

